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Abstract:

A vibrating device has a package having an accommodating space in the
interior thereof and a gyro element and an IC chip accommodated in the
accommodating space. The package has a plate-like bottom plate having an
IC chip mounting area and a vibrating element mounting area. The IC chip
mounting area includes an IC chip mounting surface on which the IC chip
is mounted. The vibrating element mounting area is arranged in parallel
with the IC chip mounting area and includes a vibrating element mounting
surface on which the gyro element is mounted. The thickness of the IC
chip mounting area is smaller than that of the vibrating element mounting
area. The IC chip mounting surface is located closer to a bottom side
than the vibrating element mounting surface.

Claims:

1. A vibrating device comprising: a package having an accommodating space
in the interior thereof; and a vibrating element and an IC chip
accommodated in the accommodating space, wherein the package has a bottom
portion having an IC chip mounting area and a vibrating element mounting
area, the IC chip mounting area including an IC chip mounting surface on
which the IC chip is mounted, the vibrating element mounting area being
disposed in parallel with the IC chip mounting area and including a
vibrating element mounting surface on which the vibrating element is
mounted, the thickness of the bottom portion is smaller in the IC chip
mounting area than in the vibrating element mounting area, and the IC
chip mounting surface is located closer to a rear surface side of the
bottom portion than the vibrating element mounting surface, the rear
surface side being with respect to the mounting surfaces of the IC chip
and the vibrating element.

2. The vibrating device according to claim 1, wherein the thickness of
the vibrating element is smaller than that of the IC chip.

3. The vibrating device according to claim 1, wherein the vibrating
element is supported at both sides thereof on the vibrating element
mounting surface.

4. The vibrating device according to claim 1, wherein the bottom portion
has a recess which is opened in the vibrating element mounting surface
and prevents contact with the vibrating element.

5. The vibrating device according to claim 1, wherein the vibrating
element has a vibrating portion which vibrates, and the vibrating element
mounting surface includes, in the planar view of the bottom portion, a
recess which includes in the interior thereof at least one portion of the
vibrating portion.

6. The vibrating device according to claim 1, wherein the bottom portion
has a regulating portion which regulates displacement of the vibrating
element toward the thickness direction.

7. The vibrating device according to claim 6, wherein at least one
portion of the regulating portion faces a base portion of the vibrating
element.

8. The vibrating device according to claim 1, further comprising a buffer
layer disposed between the vibrating element mounting surface and the
vibrating element.

9. The vibrating device according to claim 1, wherein a through-hole
which communicates between the interior and exterior of the accommodating
space is disposed in the bottom portion, and the through-hole is
disposed, in the planar view of the bottom portion, on the side opposite
to the vibrating element via the IC chip.

10. The vibrating device according to claim 9, wherein the through-hole
is disposed in a thicker area of the bottom portion than the IC chip
mounting area.

11. The vibrating device according to claim 1, wherein the vibrating
element is a gyro element which detects an angular velocity.

12. An electronic apparatus comprising the vibrating device according to
claim 1.

Description:

BACKGROUND

[0001] 1. Technical Field

[0002] The present invention relates to a vibrating device and an
electronic apparatus.

[0003] 2. Related Art

[0004] Heretofore, vibrating devices in which a sensor chip and an IC
(Integrated Circuit) are disposed within a casing have been known (for
example, refer to JP-A-2006-261560 (Patent Document 1)).

[0005] A vibrating device (semiconductor package) of Patent Document 1 has
a case body having a bottom plate and a frame-like side wall disposed at
a peripheral edge portion of an upper surface of the bottom plate. A
sensor chip such as an acceleration sensor, a signal processing chip, and
a memory chip are mounted on the upper surface of the bottom plate so as
to be located in a chip accommodating space formed in the interior of the
case body.

[0006] Moreover, in the vibrating device of Patent Document 1, the signal
processing chip and the memory chip are arranged to be overlapped with
each other in the thickness direction, and the sensor chip is arranged in
parallel next to them. The bottom plate is designed such that the
thickness of a sensor chip mounting area in which the sensor chip is
mounted is smaller than that of a signal processing chip mounting area in
which the signal processing chip and the memory chip are arranged to be
overlapped with each other. In other words, the bottom plate has a shape
in which one portion (portion corresponding to the sensor chip mounting
area) of the upper surface is recessed lower than the other portion
(portion corresponding to the signal processing chip mounting area). In
the recessed portion, the sensor chip is mounted. In the vibrating device
of Patent Document 1, by mounting the sensor chip having a thickness
greater than that of the signal processing chip or the memory chip in the
recessed portion, miniaturization (reduction in profile) of the vibrating
device is achieved.

[0007] In the vibrating device of Patent Document 1, however, the
thickness of the sensor chip mounting area of the bottom plate is
reduced, and the sensor chip is mounted in the thickness-reduced portion.
The thickness-reduced portion is easy to deform (easy to strain) due to
an external force or heat, compared to the other portion (signal
processing chip mounting area). Then, due to deformation occurring in the
portion, an unexpected external force (stress) is applied to the sensor
chip, thereby reducing detection accuracy of the sensor chip.

[0008] In this manner, the vibrating device of Patent Document 1 has a
problem that it is impossible to achieve miniaturization while preventing
a reduction in characteristics.

SUMMARY

[0009] An advantage of some aspects of the invention is to provide a
vibrating device which can achieve miniaturization while preventing a
reduction in characteristics of a vibrating element due to strain, and an
electronic apparatus.

Application Example 1

[0010] This application example of the invention is directed to a
vibrating device including: a package having an accommodating space in
the interior thereof; and a vibrating element and an IC chip accommodated
in the accommodating space, wherein the package has a bottom portion
having an IC chip mounting area and a vibrating element mounting area,
the IC chip mounting area including an IC chip mounting surface on which
the IC chip is mounted, the vibrating element mounting area being
disposed in parallel with the IC chip mounting area and including a
vibrating element mounting surface on which the vibrating element is
mounted, the thickness of the bottom portion is smaller in the IC chip
mounting area than in the vibrating element mounting area, and the IC
chip mounting surface is located closer to a rear surface side of the
bottom portion than the vibrating element mounting surface, the rear
surface side being with respect to the mounting surfaces of the IC chip
and the vibrating element.

[0011] With this configuration, it is possible to provide a vibrating
device which can achieve miniaturization (reduction in profile) while
preventing a reduction in characteristics of a vibrating element due to
strain.

Application Example 2

[0012] In the vibrating device according to the above application example
of the invention, it is preferable that the thickness of the vibrating
element is smaller than that of the IC chip.

[0013] With this configuration, the vibrating device can be further
miniaturized (reduced in profile).

Application Example 3

[0014] In the vibrating device according to the above application example
of the invention, it is preferable that the vibrating element is
supported at both sides thereof on the vibrating element mounting
surface.

[0015] With this configuration, the held state and vibration
characteristics of the vibrating element are stabilized.

Application Example 4

[0016] In the vibrating device according to the above application example
of the invention, it is preferable that the bottom portion has a recess
which is opened in the vibrating element mounting surface and prevents
contact with the vibrating element.

[0017] With this configuration, it is possible to effectively prevent or
suppress breakage and damage of the vibrating element caused by contact
between the vibrating element mounting surface and the vibrating element
due to an impact such as dropping.

Application Example 5

[0018] In the vibrating device according to the above application example
of the invention, it is preferable that the vibrating element has a
vibrating portion which vibrates, and that the vibrating element mounting
surface includes, in the planar view of the bottom portion, a recess
which includes in the interior thereof at least one portion of the
vibrating portion.

[0019] With this configuration, the recess can be efficiently formed, and
a reduction in rigidity of the vibrating element mounting area can be
prevented or suppressed.

Application Example 6

[0020] In the vibrating device according to the above application example
of the invention, it is preferable that the bottom portion has a
regulating portion which regulates displacement of the vibrating element
toward the thickness direction.

[0021] With this configuration, excessive deformation of the vibrating
element can be prevented, so that breakage and damage of the vibrating
element can be prevented or suppressed.

Application Example 7

[0022] In the vibrating device according to the above application example
of the invention, it is preferable that at least one portion of the
regulating portion faces a base portion of the vibrating element.

[0023] With this configuration, excessive deformation of the vibrating
element can be prevented, and also influence on vibration characteristics
can be reduced.

Application Example 8

[0024] In the vibrating device according to the above application example
of the invention, it is preferable that the vibrating device further
includes a buffer layer disposed between the vibrating element mounting
surface and the vibrating element.

[0025] With this configuration, when the vibrating element is greatly
displaced due to excessive deformation in the thickness direction, the
vibrating element is brought into contact with the buffer layer and the
impact is absorbed and relieved. Therefore, breakage and damage of the
vibrating element can be prevented or suppressed.

Application Example 9

[0026] In the vibrating device according to the above application example
of the invention, it is preferable that a through-hole which communicates
between the interior and exterior of the accommodating space is disposed
in the bottom portion, and that the through-hole is disposed, in the
planar view of the bottom portion, on the side opposite to the vibrating
element via the IC chip.

[0027] With this configuration, it is possible to more reliably prevent or
suppress a change in characteristics of the vibrating element due to
strain.

Application Example 10

[0028] In the vibrating device according to the above application example
of the invention, it is preferable that the through-hole is disposed in a
thicker area of the bottom portion than the IC chip mounting area.

[0029] With this configuration, it is possible to more reliably prevent or
suppress a change in characteristics of the vibrating element due to
strain.

Application Example 11

[0030] In the vibrating device according to the above application example
of the invention, it is preferable that the vibrating element is a gyro
element which detects an angular velocity.

[0031] With this configuration, it is possible to obtain a vibrating
device which can detect an angular velocity.

Application Example 12

[0032] This application example of the invention is directed to an
electronic apparatus including the vibrating device according to the
above application example of the invention.

[0033] With this configuration, an electronic apparatus with high
reliability is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention will be described with reference to the accompanying
drawings, wherein like numbers reference like elements.

[0035]FIG. 1 is a cross-sectional view showing a first embodiment of a
vibrating device according to the invention.

[0036] FIGS. 2A and 2B are plan views of a gyro element included in the
vibrating device shown in FIG. 1.

[0037] FIGS. 3A and 3B are plan views explaining the driving of the gyro
element shown in FIGS. 2A and 2B.

[0043]FIG. 9 is a plan view showing a modified example of a recess of the
vibrating device shown in FIG. 7.

[0044]FIG. 10 is a cross-sectional view of a vibrating device according
to a fourth embodiment of the invention.

[0045] FIG. 11 is a cross-sectional view of a vibrating device according
to a fifth embodiment of the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0046] Hereinafter, a vibrating device and an electronic apparatus
according to the invention will be described in detail based on
embodiments shown in the accompanying drawings.

First Embodiment

[0047] First, a first embodiment of a vibrating device according to the
invention will be described.

[0048]FIG. 1 is a cross-sectional view showing the first embodiment of
the vibrating device according to the invention. FIGS. 2A and 2B are plan
views of a gyro element included in the vibrating device shown in FIG. 1.
FIGS. 3A and 3B are plan views explaining the driving of the gyro element
shown in FIGS. 2A and 2B. FIG. 4 is a plan view of the vibrating device
shown in FIG. 1. FIG. 5 is a cross-sectional view showing one example of
a manufacturing method of a base of the vibrating device shown in FIG. 1.

[0049] In the following, the upper side in FIG. 1 is referred to as
"upper", the lower side is referred to as "lower", the right side is
referred to as "right", and the left side is referred to as "left", for
convenience of description. Moreover, as shown in FIG. 1, three axes
perpendicular to each other are referred to as x-axis, y-axis, and
z-axis. The z-axis coincides with the thickness direction of the
vibrating device. Moreover, a direction parallel to the x-axis is
referred to as "x-axis direction", a direction parallel to the y-axis is
referred to as "y-axis direction", and a direction parallel to the z-axis
is referred to as "z-axis direction".

[0050] The vibrating device 1 shown in FIG. 1 has a gyro element
(vibrating element) 2, an IC chip 3 which controls the driving or the
like of the gyro element 2, and a package 4 which accommodates the gyro
element 2 and the IC chip 3.

[0051] Although a gyro element is used as a vibrating element in the
vibrating device 1 of the embodiment, a vibrating element to be used is
not limited to a gyro element. For example, an acceleration sensor, an AT
vibrator (oscillator), or the like may be used.

[0052] Hereinafter, these will be sequentially described in detail.

Gyro Element 2

[0053] Hereinafter, the gyro element 2 will be described based on FIGS. 2A
and 2B and FIGS. 3A and 3B. Here, FIG. 2A is a plan view of an upper
surface seen from above (a lid 7 side), and FIG. 2B is a plan view
(perspective view) of a lower surface seen from above. In FIGS. 2A and
2B, electrodes and terminals are hatched for convenience of description.
In FIGS. 3A and 3B, illustrations of supporting portions, beams,
electrodes, and the like are omitted for convenience of description.

[0054] The gyro element 2 is a so-called "in-plane detection-type" sensor
which detects an angular velocity about the z-axis. As shown in FIGS. 2A
and 2B, the gyro element 2 is composed of a vibrating reed 21, and a
plurality of electrodes, wirings, and terminals formed on the surfaces of
the vibrating reed 21.

[0055] The vibrating reed 21 is of a so-called double-T-type. The
vibrating reed 21 can be composed of a piezoelectric material such as
quartz crystal, lithium tantalate, or lithium niobate. However, quartz
crystal is preferable among them. With this configuration, the vibrating
reed 21 which can provide excellent vibration characteristics (frequency
characteristics) is obtained.

[0056] The vibrating reed 21 extends in the xy plane and has its thickness
in the z-axis direction. The vibrating reed 21 has a base portion 22
located at the center, a pair of detecting vibration arms 231 and 232
each extending outwardly from the base portion 22 in the y-axis
direction, a pair of coupling arms 241 and 242 each extending outwardly
from the base portion 22 in the x-axis direction, a pair of driving
vibration arms 251 and 252 each extending outwardly from a tip portion of
the coupling arm 241 in the y-axis direction, and a pair of driving
vibration arms 253 and 254 each extending outwardly from a tip portion of
the coupling arm 242 in the y-axis direction. Moreover, the vibrating
reed 21 has a pair of supporting portions 261 and 262 arranged to face
each other via the base portion 22 in the y-axis direction and four beams
271, 272, 273, and 274 coupling the supporting portions 261 and 262 with
the base portion 22.

[0057] At a tip portion of each of the detecting vibration arms 231 and
232 and the driving vibration arms 251 to 254, a weight portion which is
substantially quadrilateral and has a width greater than that thereof on
its base-end side is formed. By disposing the weight portion, detection
sensitivity of the gyro element 2 for angular velocity is improved.

[0058] The supporting portions 261 and 262 each extend in the x-axis
direction. The other portions constituting the vibrating reed 21 are
located between these supporting portions 261 and 262. The supporting
portion 261 is coupled with the base portion 22 via the beams 271 and
272. The supporting portion 262 is coupled with the base portion 22 via
the beams 273 and 274.

[0059] The beam 271 passes through between the detecting vibration arm 231
and the driving vibration arm 251 to couple the supporting portion 261
with the base portion 22. The beam 272 passes through between the
detecting vibration arm 231 and the driving vibration arm 253 to couple
the supporting portion 261 with the base portion 22. The beam 273 passes
through between the detecting vibration arm 232 and the driving vibration
arm 252 to couple the supporting portion 262 with the base portion 22.
The beam 274 passes through between the detecting vibration arm 232 and
the driving vibration arm 254 to couple the supporting portion 262 with
the base portion 22.

[0060] The beams 271, 272, 273, and 274 each have a serpentine portion
(S-shaped portion) which extends in the y-axis direction while
reciprocating in the x-axis direction, thereby having elasticity in the
x-axis direction and the y-axis direction.

[0061] Moreover, since the beams 271, 272, 273, and 274 each have an
elongated shape with the serpentine portion, the beams 271, 272, 273, and
274 have elasticity in all directions.

[0062] Therefore, even when an external impact is applied, an effect of
absorbing the impact is provided by the beams 271, 272, 273, and 274.
Therefore, it is possible to reduce or suppress detection noise due to
the impact.

[0063] The configuration of the vibrating reed 21 has been described so
far. On the surfaces of the vibrating reed 21, the plurality of
electrodes, wirings, and terminals are formed.

[0064] Specifically, a detecting signal electrode 281 is formed on upper
and lower surfaces of the detecting vibration arm 231. Similarly, a
detecting signal electrode 281 is formed on upper and lower surfaces of
the detecting vibration arm 232.

[0065] The pair of detecting signal electrodes 281 formed on the detecting
vibration arm 231 are electrically connected, via wirings (not shown)
formed on the surfaces of the vibrating reed 21, to detecting signal
terminals 291a formed on the supporting portion 261. The pair of
detecting signal electrodes 281 formed on the detecting vibration arm 232
are electrically connected, via wirings (not shown) formed on the
surfaces of the vibrating reed 21, to detecting signal terminals 291b
formed on the supporting portion 262.

[0066] Moreover, a detecting ground electrode 282 is formed on side
surfaces of the detecting vibration arm 231 and upper and lower surfaces
of the weight portion of the detecting vibration arm 231. Similarly, a
detecting ground electrode 282 is formed also on side surfaces of the
detecting vibration arm 232 and upper and lower surfaces of the weight
portion of the detecting vibration arm 232.

[0067] The pair of detecting ground electrodes 282 formed on the detecting
vibration arm 231 are electrically connected, via wirings (now shown)
formed on the surfaces of the vibrating reed 21, to detecting ground
terminals 292a formed on the supporting portion 261. The pair of
detecting ground electrodes 282 formed on the detecting vibration arm 232
are electrically connected, via wirings (not shown) formed on the
surfaces of the vibrating reed 21, to detecting ground terminals 292b
formed on the supporting portion 262. The detecting ground electrode 282
has a potential serving as a ground with respect to the detecting signal
electrode 281.

[0068] By forming the detecting signal electrodes 281 and the detecting
ground electrodes 282 with the arrangement described above, detecting
vibration generated in the detecting vibration arm 231 appears as
electric charge between the detecting signal electrode 281 and the
detecting ground electrode 282 formed on the detecting vibration arm 231,
and can be extracted as a signal from the detecting signal terminal 291a
and the detecting ground terminal 292a formed on the supporting portion
261. Moreover, detecting vibration generated in the detecting vibration
arm 232 appears as electric charge between the detecting signal electrode
281 and the detecting ground electrode 282 formed on the detecting
vibration arm 232, and can be extracted as a signal from the detecting
signal terminal 291b and the detecting ground terminal 292b formed on the
supporting portion 262.

[0069] Moreover, a driving signal electrode 283 is formed on upper and
lower surfaces of the driving vibration arm 251. Similarly, a driving
signal electrode 283 is formed also on upper and lower surfaces of the
driving vibration arm 252. Moreover, a driving signal electrode 283 is
formed also on side surfaces of the driving vibration arm 253 and upper
and lower surfaces of the weight portion of the driving vibration arm
253. Similarly, a driving signal electrode 283 is formed also on side
surfaces of the driving vibration arm 254 and upper and lower surfaces of
the weight portion of the driving vibration arm 254. These plurality of
driving signal electrodes 283 are electrically connected, via wirings
(not shown) formed on the surfaces of the vibrating reed 21, to driving
signal terminals 293a formed on the supporting portion 261.

[0070] Moreover, a driving ground electrode 284 is formed on side surfaces
of the driving vibration arm 251 and upper and lower surfaces of the
weight portion of the driving vibration arm 251. Similarly, a driving
ground electrode 284 is formed also on side surfaces of the driving
vibration arm 252 and upper and lower surfaces of the weight portion of
the driving vibration arm 252. Moreover, a driving ground electrode 284
is formed also on upper and lower surfaces of the driving vibration arm
253. Similarly, a driving ground electrode 284 is formed also on upper
and lower surfaces of the driving vibration arm 254. These plurality of
driving ground electrodes 284 are electrically connected, via wirings
(not shown) formed on the surfaces of the vibrating reed 21, to driving
ground terminals 293b formed on the supporting portion 262. The driving
ground electrode 284 has a potential serving as a ground with respect to
the driving signal electrode 283.

[0071] When the driving signal electrodes 283 and the driving ground
electrodes 284 are formed with the arrangement described above, an
electric field is generated between the driving signal electrode 283 and
the driving ground electrode 284 formed on each of the driving vibration
arms 251, 252, 253, and 254 by applying a driving signal between the
driving signal terminal 293a and the driving ground terminal 293b,
thereby making it possible to drive and vibrate each of the driving
vibration arms 251, 252, 253, and 254.

[0072] For these electrodes, terminals, and wirings, for example, one
obtained by applying gold plating to an under layer formed on the
surfaces of the vibrating reed 21 and composed of chromium can be used.
With this configuration, adhesion between the electrodes or the like and
the vibrating reed 21 is improved, so that the reliability of the gyro
element 2 is improved.

[0073] The gyro element 2 having the configuration described above detects
an angular velocity ω about the z-axis as follows. In the gyro
element 2, when an electric field is generated between the driving signal
electrode 283 and the driving ground electrode 284 in a state where the
angular velocity ω is not applied, the driving vibration arms 251,
252, 253, and 254 perform bending vibration in directions shown by
double-headed arrows A as shown in FIG. 3A. In this case, since the
driving vibration arms 251 and 252 and the driving vibration arms 253 and
254 vibrate plane-symmetrically with respect to the yz plane passing
through a central point G (center of gravity G), the base portion 22, the
coupling arms 241 and 242, and the detecting vibration arms 231 and 232
hardly vibrate.

[0074] When the angular velocity Ct) about the z-axis is applied to the
gyro element 2 in a state of performing this driving vibration, the gyro
element 2 vibrates as shown in FIG. 3B. That is, the Coriolis force in
directions of double-headed arrows B acts on the driving vibration arms
251, 252, 253, and 254 and the coupling arms 241 and 242, and in response
to vibration in the directions of the double-headed arrows B, detecting
vibration in directions of double-headed arrows C is excited. Then, the
strain of the detecting vibration arms 231 and 232 caused by this
vibration is detected by the detecting signal electrode 281 and the
detecting ground electrode 282 to obtain the angular velocity ω.

IC Chip

[0075] The IC chip 3 is an electron device formed by integrating a driving
circuit (oscillator circuit) which drives (oscillates) the gyro element
2, a detector circuit including a charge amplifier, and the like. That
is, the IC chip 3 is an electron device which outputs an electric signal
to the driving signal electrode 283 of the gyro element 2 and receives
and processes an electric signal from the detecting signal electrode 281
to obtain the angular velocity ω about the z-axis.

Package

[0076] The package 4 accommodates the gyro element 2 and the IC chip. The
package 4 has, in the planar view thereof (the xy-plane view),
substantially a rectangular shape extending in the x-axis direction, and
accommodates the gyro element 2 and the IC chip 3 in a state where they
are arranged side by side in the x-axis direction.

[0077] As shown in FIG. 1, the package 4 has a base 10 having a recess
opened in its upper surface and the lid 7 bonded to the base so as to
cover the opening of the recess. The base 10 has a plate-like bottom
plate (bottom portion) 5 and a frame-like side wall 6 disposed at a
peripheral edge portion of an upper surface of the bottom plate 5. The
package 4 has an accommodating space 4a in the interior thereof. Within
the accommodating space 4a, the gyro element 2 and the IC chip 3 are
airtightly accommodated and mounted.

[0078] As shown in FIG. 1, the bottom plate 5 has a flat lower surface 51
and an upper surface 52 having a step. The upper surface 52 has a gyro
element mounting surface (vibrating element mounting surface) 521 which
is located at an upper stage portion of the step and on which the gyro
element 2 is mounted, and an IC chip mounting surface 522 which is
located at a lower stage portion of the step and on which the IC chip 3
is mounted.

[0079] The IC chip 3 is mounted on and fixed to the IC chip mounting
surface 522 via conductive adhesive 91 such as silver paste. With this
configuration, a lower surface of the IC chip 3 can be grounded, which
stabilizes a reference potential.

[0080] As shown in FIG. 4, a plurality of IC pads 31 are formed on an
upper surface of the IC chip 3. On the other hand, a connection pad 81
corresponding to each of the IC pads 31 is formed at the upper stage
portion (the periphery of the IC chip 3) of the upper surface 52 of the
bottom plate 5. The connection pad 81 and the IC pad 31 are electrically
connected via a wire (bonding wire). Moreover, each of the connection
pads 81 is electrically connected, via a conductive post (not shown) or
the like formed in the bottom plate 5, to an external mount terminal (not
shown) formed on the lower surface 51 of the bottom plate 5. With this
configuration, electrical connection from the outside of the package 4 to
the IC ship 3 can be achieved.

[0081] For each of the connection pads 81, for example, one obtained by
applying gold plating to an under layer formed on the upper surface 52 of
the bottom plate 5 and composed of chromium can be used. With this
configuration, adhesion between the connection pad 81 and the bottom
plate 5 is improved, so that the reliability of the vibrating device 1 is
improved. The configuration described above is similarly applied to a
connection pad 82 described later.

[0082] As shown in FIG. 1, it is preferable that the upper surface of the
IC chip 3 is located lower than an upper surface of the gyro element 2.
With this configuration, a space for arranging bonding wires between the
IC chip 3 and the lid 7 can be sufficiently assured while achieving a
reduction in profile of the vibrating device 1. Therefore, for example,
contact between the lid 7 and bonding wires is easily prevented, and an
electrical connection state between the IC pad 31 and the connection pad
81 can be maintained more reliably, so that the reliability of the
vibrating device 1 is improved.

[0083] The location of the upper surface of the IC chip is not limited to
that. For example, the upper surface of the IC chip may coincide with the
upper surface of the gyro element 2, or may be located higher than the
upper surface of the gyro element 2.

[0084] In the gyro element 2, each of the supporting portions 261 and 262
is mounted on and fixed to the gyro element mounting surface 521 via
conductive fixing members (conductive adhesive) 92 such as solder. The
supporting portions 261 and 262 are located at both ends of the gyro
element 2 in the y-axis direction. Therefore, by fixing the supporting
portions to the bottom plate 5, the gyro element 2 is supported at the
both sides thereof on the bottom plate 5. Therefore, the gyro element 2
can be stably mounted on the bottom plate 5, and unwanted vibrations
(vibrations other than vibration desired to be detected) of the gyro
element 2 are suppressed, so that the detection accuracy of the gyro
element 2 for angular velocity is improved.

[0085] Six conductive fixing members 92 are disposed corresponding to (in
contact with) the detecting signal terminals 291a and 291b, the detecting
ground terminals 292a and 292b, the driving signal terminal 293a, and the
driving ground terminal 293b which are formed on the supporting portions
261 and 262, and separated from each other. On the gyro element mounting
surface 521, six connection pads 82 corresponding to the detecting signal
terminals 291a and 291b, the detecting ground terminals 292a and 292b,
the driving signal terminal 293a, and the driving ground terminal 293b
are formed. Each of the connection pads 82 and any of the terminals
corresponding thereto are electrically connected via the conductive
fixing member 92. Moreover, the connection pads 82 are electrically
connected to the IC ship 3 via wirings (not shown) formed on the upper
surface of the bottom plate 5 or in the interior thereof for example.

[0086] With this configuration described above, since the conductive
fixing member 92 can be used as a fixing member for fixing the gyro
element 2 to the bottom plate 5 and as a connecting member for performing
electrical connection with the gyro element 2, the configuration of the
vibrating device 1 can be simplified.

[0087] Moreover, the conductive fixing members 92 form a gap between the
gyro element 2 and the bottom plate 5, and are each used as a gap member
which prevents contact between the gyro element 2 and the bottom plate 5.
With this configuration, breakage and damage of the gyro element 2 due to
contact with the bottom plate 5 can be prevented, so that the vibrating
device 1 which can detect an angular velocity accurately and provide
excellent reliability is provided. The gap is preferably short unless it
hinders the driving of the gyro element 2. With this configuration,
excessive deformation of the gyro element 2 (the vibrating reed 21) due
to contact of the gyro element 2 with the bottom plate 5 is prevented
when an impact in the z-axis direction is applied to the vibrating device
1, so that breakage and damage of the gyro element 2 can be effectively
suppressed.

[0088] As described above, the upper surface 52 of the bottom plate 5 has
the gyro element mounting surface 521 on which the gyro element 2 is
mounted and the IC chip mounting surface 522 which is located lower
(bottom side) than the gyro element mounting surface 521 and on which the
IC chip 3 is mounted.

[0089] In the vibrating device 1, the thickness (length in the z-axis
direction) of the IC chip 3 is greater than that of the gyro element 2
with recent miniaturization of the gyro element 2. For example, whereas
the thickness of the gyro element 2 is about 100 μm, the thickness of
the IC chip 3 is about 200 μm. Therefore, the IC chip mounting surface
522 is located lower than the gyro element mounting surface 521, and the
IC chip 3 is mounted on the IC chip mounting surface 522, whereby a
reduction in profile of the vibrating device 1 can be achieved, and the
vibrating device 1 can be miniaturized.

[0090] Moreover, as shown in FIG. 1, the bottom plate 5 has a gyro element
mounting area (vibrating element mounting area) S1 including the gyro
element mounting surface 521 and an IC chip mounting area S2 including
the IC chip mounting surface 522. The gyro element mounting area S1 is
configured such that the thickness thereof is greater than that of the IC
chip mounting area S2. By mounting the gyro element 2 in the gyro element
mounting area S1 which is a portion having the thickness described above,
a reduction in detection accuracy of the gyro element 2 can be prevented
or suppressed.

[0091] Specifically, the application of strain to the vibrating reed 21
affects vibration characteristics, which may reduce detection accuracy
for angular velocity. Typical causes of the application of strain to the
vibrating reed 21 includes, for example, deformation of the package 4 due
to the application of an external force and deformation of the package 4
due to thermal expansion or thermal shrinkage (thermal stress).

[0092] When the package 4 is deformed due to an external force or thermal
stress, the relative positional relation (separate distance) among the
six conductive fixing members 92 which fix the gyro element 2 to the
bottom plate 5 changes. Stress in response to the change is applied to
the vibrating reed 21, so that the vibrating reed 21 is strained. In the
case where thermal stress causes the deformation, if the coefficients of
linear expansion of the bottom plate 5 and the vibrating reed 21 are
equal to each other, strain is not substantially applied to the vibrating
reed 21 because even when the package 4 deforms (expands or shrinks), the
vibrating reed 21 also deforms to the same degree as the deformation of
the package 4. However, since the coefficients of linear expansion of the
bottom plate 5 and the vibrating reed 21 are different from each other,
strain is applied to the vibrating reed 21, similarly to the case of an
external force, also in the case where thermal stress causes the
deformation.

[0093] Particularly in the vibrating device 1 of the embodiment, the gyro
element 2 is supported at the both sides thereof on the bottom plate 5.
Therefore, the stress (particularly stress in the y-axis direction)
applied to the vibrating reed 21 cannot be released, so that strain is
easily applied to the vibrating reed 21.

[0094] Therefore, in the vibrating device 1 as described above, the gyro
element 2 is mounted in the gyro element mounting area S1 (on the gyro
element mounting surface 521), whereby the application of strain to the
vibrating reed 21 is prevented or suppressed to prevent or suppress a
reduction in detection accuracy of the gyro element 2.

[0095] Since the gyro element mounting area S1 has a thickness greater
than that of the other portion (the IC chip mounting area S2) of the
bottom plate 5, the gyro element mounting area S1 has correspondingly
higher rigidity. Therefore, compared to the other portion of the bottom
plate 5, deformation due to an external force or thermal stress is
unlikely to occur. Moreover, even if the deformation occurs, the degree
of the deformation is small. By mounting the gyro element 2 in the gyro
element mounting area S1 which is unlikely to deform as described above,
the application of strain to the gyro element 2 can be prevented or
suppressed. As a result, a reduction in detection accuracy of the gyro
element 2 can be prevented or suppressed.

[0096] The thickness of the gyro element mounting area S1 is preferably
from about 0.3 mm to 0.8 mm even though it varies depending on a
constituent material. With this configuration, the deformation of the
gyro element mounting area S1 can be more effectively prevented or
suppressed while achieving a reduction in profile of the vibrating device
1.

[0097] In the bottom plate 5, a through-hole 53 as a sealing hole is
formed. The through-hole 53 is a hole for causing the interior of the
accommodating space 4a to be a reduced-pressure environment (preferably a
vacuum). By causing the interior of the accommodating space 4a to be a
reduced-pressure environment, an increase in CI value of the vibrating
reed 21 due to the viscosity of air can be prevented or suppressed.

[0098] A method of reducing the pressure in the interior of the
accommodating space 4a is not particularly limited, and includes, for
example, a method of first removing air in the interior of the
accommodating space 4a via the through-hole 53, placing a metal ball in
the through-hole 53, irradiating the metal ball with a laser beam to melt
the metal ball, and then covering to seal the through-hole 53. A step
portion 531 which blocks the passing of the metal ball is formed in the
through-hole 53, thereby making it easy to melt the metal ball within the
through-hole. Specifically, the step portion 531 is formed at the
boundary between a portion formed on the lower surface 51 side and having
an inside diameter greater than the outside diameter of the metal ball
and a portion formed on the upper surface 52 side and having an inside
diameter smaller than the outside diameter of the metal ball.

[0099] As shown in FIGS. 1 and 4, the through-hole 53 is formed, in the
xy-plane view, on the side opposite to the gyro element 2 via the IC chip
3. That is, the through-hole 53 is formed at a location as far as
possible from the gyro element 2. Moreover, the through-hole 53 is formed
at a thick portion of the bottom plate 5, in other words, at a portion
other than the IC chip mounting area S2 and having a thickness greater
than that of the IC chip mounting area S2. In the embodiment, the
through-hole 53 is formed at a portion having the same thickness as that
of the gyro element mounting area S1. By forming the through-hole 53 at
the location described above, the following effects can be obtained.

[0100] As described above, the through-hole 53 is covered by melting the
metal ball by laser irradiation. Therefore, as described above, the
through-hole 53 is formed at a location as far as possible from the gyro
element 2, whereby deformation, degradation, or the like of the gyro
element 2 due to heat in laser irradiation can be prevented.

[0101] Moreover, the temperature at the periphery of the through-hole 53
is raised due to heat in laser irradiation, causing thermal expansion of
the periphery of the through-hole 53. Due to the occurrence of the
thermal expansion, stress may remain at the periphery of the through-hole
53 in the bottom plate 5 after sealing. Therefore, the through-hole 53 is
formed at a location as far as possible from the gyro element 2, whereby
it is possible to prevent or suppress a change in vibration
characteristics of the vibrating reed 21 due to the stress (strain)
remaining at the periphery of the through-hole 53, so that a change in
detection characteristics of the gyro element 2 can be prevented or
suppressed. Moreover, it is possible to prevent or suppress a change in
vibration characteristics of the vibrating reed 21 also due to a temporal
change in residual stress.

[0102] In the embodiment as described above, since the through-hole 53 is
formed at a thick portion with high rigidity, deformation itself due to
the residual stress at the peripheral portion of the through-hole 53 can
be effectively prevented or suppressed. Therefore, it is possible to more
reliably prevent or suppress the occurrence of the problems described
above. Moreover, a crack is likely to occur from the through-hole 53 due
to heat generated by excess current occurring when the lid 7 is
seam-welded to the base 10 as will be described later. However, by
forming the through-hole 53 at a thick portion with high rigidity, the
occurrence of the crack can be effectively prevented or suppressed.

[0103] The arrangement of the through-hole 53 is not limited to that. For
example, the through-hole 53 may be formed, in the xy-plane view, on the
side opposite to the gyro element 2 via the IC chip 3, in the bottom
plate 5 having the same thickness as that of the IC chip mounting surface
522. Even with the mode described above, it is possible to prevent or
suppress a change in vibration characteristics of the vibrating reed 21
due to the stress (strain) remaining at the periphery of the through-hole
53, so that a change in detection characteristics of the gyro element 2
can be prevented or suppressed.

[0104] The constituent material of the base 10 is not particularly
limited, and various kinds of ceramics such as aluminum oxide can be
used. When the base 10 having the mode described above is manufactured
from the constituent material described above, a laminated body is formed
by laminating, as shown in FIG. 5, at least one flat plate-like substrate
10a corresponding to the shape of the bottom plate 5 in the planar view,
at least one frame-like substrate 10b corresponding to the shape of the
upper stage portion of the bottom plate 5 in the planar view, and at
least one flat plate-like substrate 10c corresponding to the shape of the
side wall 6 in the planar view, and the laminated body is baked. With
this configuration, the base 10 can be manufactured simply.

[0105] The constituent material of the lid 7 is not particularly limited.
However, it is desirable that the constituent material is a member having
a coefficient of linear expansion close to that of the constituent
material of the base 10. For example, when ceramics is used as the
constituent material of the base 10 as described above, an alloy such as
Kovar is preferably used. The bonding between the base 10 and the lid 7
is not particularly limited. For example, they may be bonded together via
adhesive, or may be bonded by seam welding or the like.

[0106] The vibrating device 1 of the embodiment has been described so far.
According to the vibrating device, miniaturization (reduction in profile)
of the device can be achieved while preventing or suppressing a reduction
in detection characteristics for angular velocity by reducing the
influence of strain as described above. Particularly, since it is
possible to prevent or suppress a change in vibration characteristics of
the vibrating reed 21 due to strain, it is possible, for example, to
eliminate or reduce the difference between vibration characteristics in
shipping inspection and vibration characteristics in mounting on a
circuit board or the like. Therefore, excellent detection accuracy can be
provided also in mounting. Moreover, electrical characteristics are
stabilized, so that detection with higher accuracy can be performed.

Second Embodiment

[0107] Next, a second embodiment of a vibrating device according to the
invention will be described.

[0108]FIG. 6 is a cross-sectional view of the vibrating device according
to the second embodiment of the invention.

[0109] Hereinafter, the vibrating device of the second embodiment will be
described mainly on the differences from the above-described embodiment.
Descriptions of matters similar to those of the above-described
embodiment are omitted.

[0110] The vibrating device according to the second embodiment of the
invention is similar to that of the above-described first embodiment,
excepting that the location and shape of the through-hole are different.
Configurations similar to those of the above-described first embodiment
are denoted by the same reference and numeral signs.

[0111] As shown in FIG. 6, in the vibrating device 1 of the embodiment,
the through-hole 53 has an inside diameter substantially constant in the
axial direction (z-axis direction). Moreover, a portion of the
through-hole 53 overlaps with the side wall 6 in the xy-plane view. In
other words, a portion of an upper opening of the through-hole 53 is
covered by the side wall 6.

[0112] By configuring the through-hole 53 as described above, the shape of
the through-hole 53 can be simplified compared to the first embodiment.
Moreover, since the passing of the metal ball can be blocked by covering
a portion of the opening with the side wall 6, the metal ball can be
reliably melted within the through-hole 53. Moreover, for example, the
through-hole 53 can be formed at a location more separate from the gyro
element 2 compared to the first embodiment.

[0113] Also in the second embodiment, effects similar to those of the
above-described first embodiment can be provided.

Third Embodiment

[0114] Next, a third embodiment of a vibrating device according to the
invention will be described.

[0115]FIG. 7 is a cross-sectional view of the vibrating device according
to the third embodiment of the invention. FIG. 8 is a plan view of the
vibrating device shown in FIG. 7. FIG. 9 is a plan view showing a
modified example of a recess of the vibrating device shown in FIG. 7.

[0116] Hereinafter, the vibrating device of the third embodiment will be
described mainly on the difference from the above-described embodiment.
Descriptions of matters similar to those of the above-described
embodiment are omitted.

[0117] The vibrating device according to the third embodiment of the
invention is similar to that of the above-described first embodiment,
excepting that the configuration of the bottom plate is different.
Configurations similar to those of the above-described first embodiment
are denoted by the same reference and numeral signs.

[0118] As shown in FIG. 7, the bottom plate 5 has a frame-like recess 54
opened in the gyro element mounting surface 521 and a projecting portion
55 surrounded by the recess 54. The recess 54 is formed, in the xy-plane
view, so as to include in the interior thereof the detecting vibration
arms 231 and 232 and the driving vibration arms 251, 252, 253, and 254 of
the gyro element 2.

[0119] By forming the recess 54, a relatively large gap can be formed
between the bottom plate 5, and the detecting vibration arms 231 and 232
and the driving vibration arms 251, 252, 253, and 254. Therefore, an
increase in CI value of the gyro element 2 (the vibrating reed 21) due to
air resistance (viscosity of air) in the atmosphere is suppressed, so
that vibration characteristics can be stabilized.

[0120] Moreover, for example, it is possible to further reduce the amount
of difference between the leakage amount of signal of the gyro element 2
in tuning performed before sealing and the leakage amount of signal after
sealing. Therefore, the vibrating device 1 which can provide desired
characteristics (characteristics after tuning) also after sealing is
obtained.

[0121] The depth (length in the z-axis direction) of the recess 54 is not
particularly limited, and preferably, for example, from about 10 to 100
μm. With this configuration, the functions described above can be
sufficiently provided, and a reduction in rigidity of the gyro element
mounting area S1 can be suppressed.

[0122] The projecting portion (regulating portion) 55 surrounded by the
recess 54 is disposed to face the base portion 22 of the gyro element 2.
An upper surface of the projecting portion 55 is located on the same
plane with the gyro element mounting surface 521. With the projecting
portion 55, when an impact in the z-axis direction is applied to the
vibrating device 1, the base portion 22 of the gyro element 2 is brought
into contact with the projecting portion 55, so that excessive
deformation of the gyro element 2 (the vibrating reed 21) is prevented.
Therefore, breakage and damage of the gyro element 2 can be effectively
prevented. Since the base portion 22 hardly vibrates even in driving, the
problem of the degradation of vibration characteristics due to air
resistance described above hardly occurs even when the projecting portion
55 is disposed.

[0123] The shape of the recess 54 in the planar view is not particularly
limited as long as the effects described above can be provided. For
example, as shown in FIG. 9, six recesses 54 may be formed such that each
of the recesses corresponds to each arm (each vibrating portion) of the
detecting vibration arms 231 and 232 and the driving vibration arms 251,
252, 253, and 254. With this configuration, the occupancy of the recesses
54 in the gyro element mounting area S1 can be reduced, so that a
reduction in rigidity of the gyro element mounting area S1 can be more
effectively prevented or suppressed. In this case, portions located
between the six recesses 54 constitute the projecting portion 55.

[0124] In the embodiment, the upper surface of the projecting portion 55
is located on the same plane as the gyro element mounting surface 521.
However, the upper surface of the projecting portion 55 may be located
higher or lower than the gyro element mounting surface 521.

[0125] Also in the third embodiment, effects similar to those of the
above-described first embodiment can be provided.

Fourth Embodiment

[0126] Next, a fourth embodiment of a vibrating device according to the
invention will be described.

[0127]FIG. 10 is a cross-sectional view of the vibrating device according
to the fourth embodiment of the invention.

[0128] Hereinafter, the vibrating device of the fourth embodiment will be
described mainly on the difference from the above-described embodiment.
Descriptions of matters similar to those of the above-described
embodiment are omitted.

[0129] The vibrating device according to the fourth embodiment of the
invention is similar to that of the above-described first embodiment,
excepting that a buffer layer is disposed between the bottom plate (gyro
element mounting surface) and the gyro element. Configurations similar to
those of the above-described first embodiment are denoted by the same
reference and numeral signs.

[0130] As shown in FIG. 10, the vibrating device 1 of the embodiment has
the buffer layer 11 disposed on the gyro element mounting surface 521.
Then, the gyro element 2 is bonded to an upper surface of the buffer
layer 11 via the conductive fixing members 92.

[0131] Moreover, the buffer layer 11 is disposed, in the xy-plane view, so
as to include in the interior thereof the whole of the gyro element 2.

[0132] The buffer layer 11 absorbs and relieves stress transmitted from
the bottom plate 5 to the gyro element 2, or vibration leakage from the
gyro element 2, whereby the buffer layer 11 has a function of effectively
preventing or suppressing the application of strain to the gyro element 2
(the vibrating reed 21) and a change in characteristics due to vibration
leakage. With this configuration, the vibrating device 1 in which
influence due to strain and a change in characteristics due to vibration
leakage are further reduced is obtained.

[0133] It is preferable that the buffer layer 11 is composed of a material
whose linear expansivity is close to that of the constituent material
(quartz crystal) of the vibrating reed 21. By using the material
described above, the above effects can be more remarkably provided.

[0134] Moreover, it is preferable that the constituent material of the
buffer layer 11 is a material whose modulus of elasticity is from about
several GPa to several tens MPa. By using the material described above,
when an impact in the z-axis direction is applied to the vibrating device
1 for example, the gyro element 2 is brought into contact with the buffer
layer 11 and therefore the impact is absorbed and relieved, so that
breakage and damage of the gyro element 2 can be effectively prevented.

[0135] In the buffer layer 11, conductive posts (not shown) are formed.
Via the conductive post, the conductive fixing member 92 and the
connection pad 82 corresponding to the conductive fixing member 92 are
electrically connected.

[0136] Also in the fourth embodiment, effects similar to those of the
above-described first embodiment can be provided.

Fifth Embodiment

[0137] Next, a fifth embodiment of a vibrating device according to the
invention will be described.

[0138] FIG. 11 is a cross-sectional view of the vibrating device according
to the fifth embodiment of the invention.

[0139] Hereinafter, the vibrating device of the fifth embodiment will be
described mainly on the difference from the above-described embodiment.
Descriptions of matters similar to those of the above-described
embodiment are omitted.

[0140] The vibrating device according to the fifth embodiment of the
invention is similar to that of the above-described fourth embodiment,
excepting that the configuration of the buffer layer is different.
Configurations similar to those of the above-described fourth embodiment
are denoted by the same reference and numeral signs.

[0141] In the vibrating device 1 of the embodiment, the buffer layer 11 is
composed of an anisotropically conductive film (or anisotropically
conductive adhesive). The buffer layer 11 has a conductive property in
the thickness direction thereof but has an insulating property in the
plane direction. With this configuration, the conductive fixing member 92
located on the upper surface side of the buffer layer 11 can be
electrically connected with the connection pad 82 corresponding to the
conductive fixing member 92 and located on the lower surface side of the
buffer layer 11 via the buffer layer 11 while preventing a short circuit
between the plurality of connection pads 82. By using an anisotropically
conductive film as the buffer layer 11 in this manner, it is unnecessary
to form conductive posts in the buffer layer 11 unlike the
above-described fourth embodiment, so that the configuration or
manufacturing of the vibrating device 1 is simplified.

[0142] The configuration of the buffer layer 11 is not particularly
limited, and includes, for example as shown in FIG. 11, a configuration
obtained by embedding thin metal wires 11b in an insulating sheet 11a
such as of silicone such that the axis line coincides with the thickness
direction of the sheet.

[0143] Also in the fifth embodiment, effects similar to those of the
above-described first embodiment can be provided.

[0145] The vibrating device and the electronic apparatus according to the
invention have been described so far based on the embodiments shown in
the drawings. However, the invention is not limited to them, and the
configuration of each of the portions can be replaced with any
configuration having a similar function. Moreover, any another component
or process may be added. Moreover, the vibrating device according to the
invention may be one obtained by combining any two or more configurations
(features) of the embodiments.